《数字信号处理》课程教学资源（PPT课件讲稿）Chapter 06 IIR数字滤波器的设计 IIR Digital Filter Design

Chapter 6 IIR Digital Filter Design

Chapter 6 IIR Digital Filter Design

Introduce ● Digital Filter One of the most widely used complex signal processing operations is filtering whose main objective is to alter the spectrum according to some given specifications. The system implementing this operation is called a filter. The discrete-time system for the treatment of discrete-time sIgnal Is called a digital filter 2021年1月27日1时46分

2021年1月27日1时46分 Introduce ⚫ Digital Filter -- One of the most widely used complex signal processing operations is filtering, whose main objective is to alter the spectrum according to some given specifications. The system implementing this operation is called a filter. The discrete-time system for the treatment of discrete-time signal is called a digital filter

Introduce o Classification of Digital Filter According to the characterization of the eliminated frequency component, the digital filters are usually classified as ◆ Classical filters The useful frequency components in input signal are different from the eliminated frequency components ◆ Modern filters The signal is aliased into interferer frequency component 2021年1月27日1时46分

2021年1月27日1时46分 Introduce According to the characterization of the eliminated frequency component, the digital filters are usually classified as: ◆Classical filters The useful frequency components in input signal are different from the eliminated frequency components. ◆Modern filters The signal is aliased into interferer frequency component. ⚫ Classification of Digital Filter

Introduce o Classification of Digital Filter According to magnitude characteristics of the transfer function. the Classical filters include 日 Lowpass filters Highpass filters 口 Bandpass filters 口 Bandstop filters 2021年1月27日1时46分

2021年1月27日1时46分 Introduce ◆ According to magnitude characteristics of the transfer function, the Classical filters include:  Lowpass filters  Highpass filters  Bandpass filters  Bandstop filters. ⚫ Classification of Digital Filter

低通 H(eJ 2 高通 e 带通 e 带阻 图6.1.1理想低通、髙通、带通、带阻滤波器幅度特性 2021年1月27日1时46分

2021年1月27日1时46分 图6.1.1 理想低通、高通、带通、带阻滤波器幅度特性 ( e ) j H ( e ) j H ( e ) j H ( e ) j H 0 低 通 0 高 通 0 带 通 0 带 阻     −2π −2π −2π −2π −π −π −π −π π π π π 2π 2π 2π 2π

Introduce According to the length of their impulse response sequences the digital filters are usually classified as o Infinite impulse response(iir)filters ∑ 6z H( 2)三 1+>a,z k=1 o Finite impulse response(FIR) filters H()=∑n)=n 2021年1月27日1时46分

2021年1月27日1时46分 Introduce According to the length of their impulse response sequences, the digital filters are usually classified as: ◆Infinite impulse response (IIR) filters ◆Finite impulse response (FIR) filters 0 1 ( ) 1 M r r r N k k k b z H z a z − = − = = +   1 0 ( ) ( ) N n n H z h n z − − = = 

Introduce O An important step in the development of a digital filter is the determination of a realizable transfer function H(z) approximating the given frequency response specifications. the process of deriving the transfer function H(z)is called digital filter design 2021年1月27日1时46分

2021年1月27日1时46分 Introduce  An important step in the development of a digital filter is the determination of a realizable transfer function H(z) approximating the given frequency response specifications. The process of deriving the transfer function H(z) is called digital filter design

Introduce o In Chapter 5, we outlined a variety of basic structures for the realization of iir and fir transfer functions o In this chapter we consider the iir digital filter design problem. the design of FIR digital filters is discussed in Chapter 7. 2021年1月27日1时46分

2021年1月27日1时46分 Introduce  In Chapter 5, we outlined a variety of basic structures for the realization of IIR and FIR transfer functions.  In this chapter, we consider the IIR digital filter design problem. The design of FIR digital filters is discussed in Chapter 7

Content o Digital Filter specifications o Design of analog filters o Impulse Invariance Method of Lowpass iIr Digital Filters design o Bilinear transformation Method of Lowpass IIR Digital Filter Design o Design of Highpass Bandpass and Bandstop Digital Filters 2021年1月27日1时46分

2021年1月27日1时46分 Content ⚫ Digital Filter Specifications ⚫ Design of analog filters ⚫ Impulse Invariance Method of Lowpass IIR Digital Filters Design ⚫ Bilinear Transformation Method of Lowpass IIR Digital Filter Design ⚫ Design of Highpass,Bandpass and Bandstop Digital Filters

6.1 Concepts on Digital Filter There are two major issues that need to be answered before one can develop the digital transfer function G(z) a The first issue is the development of a reasonable filter frequency response specification from the requirements of overall system in which the digital filter is to be designed a The second issue is to determine whether an fir or iir digital filter is to be designed 2021年1月27日1时46分

2021年1月27日1时46分 6.1 Concepts on Digital Filter ◆There are two major issues that need to be answered before one can develop the digital transfer function G(z).  The first issue is the development of a reasonable filter frequency response specification from the requirements of overall system in which the digital filter is to be designed.  The second issue is to determine whether an FIR or IIR digital filter is to be designed